Keep using multiple credit cards and soon automatically you will keep receiving notifications regarding limit increase. No need to mail nothing unless you have to jump instantly from 50k to 5lac!
My personal exp. I started with my first CC in the year 2016 with just a 35k credit limit and today it is 7.55lac.
And I only use max 15-18% of the entire limit ever since I started using a CC so there's no condition to keep utilizing the entire or 50-80% limit for availing such benefits. In fact, using your CC to its max limit actually negatively affects ones CIBIL!
